Gasoline trap



July 26, 1960 H. J. ROCKELMAN 2,946,475

GASOLINE TRAP Filed' March 26, 1957 dfmmeys.

United States Patent 2,946,475 GASOLINE TRAP Harold J. Rockelman, 226Waverly Ave.,

Tonawanda, N.Y.

Filed Mar. 26, 1957, Ser. No. 648,712

5 Claims. (Cl. 220-18) This invention relates to a gasoline trap andmore particularly to such a trap arranged in the vent line from anunderground gasoline storage tankto prevent the discharge of any liquidgasoline from the vent pipe and hence to avoid the resulting firehazard.

At gasoline filling stations, the gasoline is stored in largeunderground tanks. These storage tanks are provided with filling pipesthrough which the tanks are usually positively filled by providing apipe fitting and forcing the gasoline under pressure through the fillingpipe into the tank. These tanks are also provided with vent lines whichterminate in vertical pipes usually attached to the sidewall of thestation house and terminating at a considerable elevation above theground. Usually each vent pipe includes a horizontal run which may be ofconsiderable length and which also is liable to develop a sag somewherealong its length. If the tank is completely filled, especially if bothit and the filling line are filled to ground level, gasoline will, ofcourse, enter the horizontal run of the vent pipe buried in the ground.Under such circumstances a body of gasoline will become trapped in thesag in the horizontal run of the vent line since it cannot return to thegasoline tank. The next.

time the tank is filled under pressure this trapped gasoline will bedriven as a body of liquid gasoline up the vertical part of the ventpipe since the gasoline is being introduced into the underground tankunder pressure and the vapor displaced from the tank can only escapethrough the vent line. As a consequence, this body of liquid gasolinewill be discharged into the atmosphere from the upper end of the ventpipe. This, of course, creates a fire hazard since any nearby flame canstart a fire which will rapidly spread to all parts sprayed by thedischarge of the liquid gasoline.

It is the principal object of the present invention to provide a simple,low cost trap for such body of gasoline driven up the vent pipe of anunderground gasoline storage tank and which will return this charge ofgasoline to the vent pipe following the filling of the tank.

Another object of the invention is to minimize the development of fumesfrom such trapping and return of the liquid gasoline, thereby to furtherminimize the fire hazard at the vent of an underground storage tank forgasoline.

Other objects and advantages of the invention will be apparent from thefollowing description and drawings in which:

Fig. 1 is a perspective view of a corner of the building of a gasolinestation having an underground gasoline storage tank and also having thegasoline trap embodying the present invention connected to the vent lineof this underground storage tank.

Fig. 2 is a fragmentary enlarged vertical section taken generally online 2-2, Fig. 1.

usually has a station house or a building, indicated at 5, and thegasoline is stored in large underground storage tanks indicatedgenerally at 6. Each of these underground storage tanks is provided witha filling line 7 extending upwardly from the top of the tank to aboveground level I and having a cap 8. In filling the tank, this cap 8 isremoved and the gasoline is usually introduced under pressure byproviding a tight fitting (not shown) which is attached to the upper endof the filling pipe 7 and through which the gasoline is forced underpositive pressure into the tank 6. The object of so positively chargingthe tank 6 is, of course, to reduce the time necessary to fill the tank.

The gasoline is removed from the tank 6 through one or more lines 9 nearthe bottom thereof and leading to the usual pumps (not shown). It isalso essential that the tank 6 have a vent line. Such a vent line leads,of course, from the upper part of the tank 6 through a suitable fitting10 and then has a horizontal run 11 which extends to the wall of thestation house 5. The vent line then has a vertical part 12 which isusually attached to the wall of the station house 15, as by thefasteners 13, and usually terminates near the roof of the station house.While usually, of course, the horizontal stretch 11 of the vent line isgiven a pitch to drain back into the gasoline tank 6, there isnecessarily some settling of the ground following the installation ofthe underground tank 6 and the underground horizontal run of, the ventpipe. Usually, also, the horizontal stretch 11 of the vent pipe passesunder the driveway used by automobiles and trucks both in filling thegasoline tank and also in obtaining gasoline from the gasoline pumps. Asa result of the settling of the ground, particularly as concentratedunder a particular area subjected to particularly heavy traffic, it notinfrequently happens that a sag 14 develops in the horizontal run of thevent line.

With the rapid filling of underground gasoline tanks under pressure, itnot infrequently happens that the tank 6 is completely filled and thatalso the vent line 7 is filled up to ground level. When this occurs, ofcourse, the horizontal run 11 of the vent line is also filled its entirelength including the sag 14. While the greater part of the gasoline sointroduced into the horizontal line 11 of the vent line will, of course,run back into the tank 6, that small body caught in the sag 14 will stayin the sag because it dips below the portion of the horizontal run ofthe vent line between it and the tank 6.

With such a body of gasoline caught in the sag 14, the next timegasoline is introduced under positive pressure through the filling line7 this body is driven along the horizontal run of the vent line 11 andup the vertical part 12 thereof and is discharged into the atmosphere asa liquid body. This not only sprays against the adjacent part of thegasoline station house 5 but also other objects which may be near andobviously creates a fire hazard since if there is any flame in thevicinity the extremely volatile gasoline will be ignited.

To avoid such a fire hazard and also to avoid the loss of the body ofgasoline by tripping it and returning it to the horizontal run 11 of thevent line, applicant has pro vided a trap embodying the presentinvention. This trap, indicated generally at 15, is preferably attachedto the upper end of the vertical part 12 of the vent line and for thispurpose is shown as having a lower dished end head 16 through which thevertical part 12 of the vent line extends and is welded as indicated at18, Fig. 2. To the rim of the dished end head 16 is secured, as bywelding, indicated at 19, a tubular or cylindrical metal shell 20 whichextends vertically to a point above the upper end of the vent pipe 12which is shown as threaded, as indicated at 21. Near its upper end thePatented July 26, 19 0 vertical shell 20 is shown as having an inwardlyextending internal annual flange 22 which supports a coarse circulardisk 23 of woven wire, this in turn supporting a finer mesh disk 24 ofwoven wire. The shell 20 is provided with an upwardly dished removableupper end head 25 the rim of which fits around the periphery of thetubular or cylindrical shell 20 and can be secured thereto by set screws26 or in any other suitable manner.

' The upper end head 25 is shown as provided with a central upwardlyextending tubular vent 28 which is externally threaded. On thisexternally threaded vent 28 is shown as screwed a sleeve 29 having adiametral cross bar 30. A cap 34 is shown as secured to this diametralcross bar 30 by means of a screw 31, this cap having a downwardlyextending flange or skirt 32 which extends below the level of the sleeve28 and is spaced a substantial distance therefrom. One or more cylinders33 of woven wire fabric are shown as fitted around the upper part of thesleeve 29 and as extending up to the underside of the cap 34particularly to insure against the entrance of foreign matter, bugs etc.into the trap.

As previously indicated the vertical part 12 of the vent pipe extends asubstantial distance up into the tubular shell 20 and to its upperthreaded end is screwed a sleege 35 having a diametral cross part or bar36. A cap 38 is secured to this cross bar 36 by means of a screw 39 andthis cap has a downwardly extending flange or skirt 40 which extendsbelow the level of the sleeve 35 and is also spaced outwardly therefrom.In order to break up the liquid gasoline discharged from the upper endof the vertical part 12 of the vent pipe, a cylinder 41 of woven wiresurrounds the upper part of the sleeve 35 and extends up to theunderside of the cap 38.

An important feature of the invention resides in the provision of drainholes 42 in the vertical part 12 of the vent pipe immediately above thelower end head 16 for the trap so that any gasoline trapped within thecylindrical shell 20 and lower end head 16 will drain back into the ventpipe 12 and hence to the horizontal stretch 11 thereof.

In operation it will be assumed that a charge or body of gasoline iscontained in the sag 14 of the horizontal run 11 of the vent pipe due toa previous filling of the tank 6 under pressure and which fillingintroduced gasoline into the horizontal run 11 of the vent pipe.

Upon the next filling of the tank 6, the cap 8 of its filling line 7 isremoved and the discharge nozzle (not shown) of the truck bringing thegasoline to the station is attached to the upper end of the charging orfilling pipe 7. The gasoline is then pumped under pressure into thefilling pipe 7, this pressurized gasoline entering the tank 6 anddisplacing the body of vapor therein. This vapor must escape through thevent line ll, 12 and since a body of gasoline is contained in the sag 14in this horizontal run 11 in the vent line, this body of gasoline isdriven under pressure up the vertical part 12 of the vent line. Thisbody of gasoline strikes the underside of the cap 38 and is drivenlaterally through the cyfindrical screen or woven mesh 41 and isdeflected downwardly by the skirt or flange 40 of the cap 38 to thebottom of the shell 20.

Accordingly this solid body of gasoline is not discharged into theatmosphere so as to create a fire hazard. Instead this body of gasolineis caught in the shell 20 where it drains back through the drain holes42 into the vent pipe. After the tank has been filled, this drain backof gasoline reenters the sag 14 and displaces any gasoline therein backinto the tank 6. The only loss of gasoline from the tank can be throughevaporation, and there is no danger at any time of the body of gasolinebeing discharged in liquid form to the atmosphere.

While the gasoline tank 6 is so being filled and also as a normal partof the venting thereof, the vapors escape through the two layers ofscreen 23, 24 and thence escape 4 through the cylindrical screen 33under the cap 32 at the extreme upper end of the trap.

From the foregoing it will be seen that the present invention provides avery simple and effective trap for gasoline which positively prevents abody of liquid gasoline being discharged from the vent pipe of anunderground tank and which insures the return of such liquid gasoline toits source. It will therefore be seen that the present invention avoidsa distinct fire hazard heretofore existent with underground storagetanks having horizontal runs in their vent lines.

I claim:

1. In an underground storage tank for gasoline or the like having a ventpipe open to the atmosphere including a subsurface horizontal run buriedat such shallow depth as to be susceptible to having a dip formedtherein by vehicles travelling on the ground thereover and also havingan upright end part projecting above ground and open at its upper end,the combination therewith of means for trapping any liquid gasolinedischarged from said open end of said vent pipe, comprising a lower endhead secured to said upper end of said vent pipe and through which saidupper end of said vent pipe extends, a tubular shell secured to andrising from the rim of said lower end head, means within said tubularshell and arranged over the open upper end of said vent pipe anddeflecting laterally any liquid discharged therefrom, said vent pipebeing provided above said lower end head with a drain hole for returningsuch discharged liquid into said vent pipe, said tubular shell beingprovided with a removable upper end head forming a cap above andenclosing the space above said deflecting means and means venting thechamber formed by said tubular shell and its end heads.

2. Apparatus as set forth in claim 1 wherein a generally horizontalscreen extends across the interior of said shell above said upper end ofsaid vent pipe.

3. In an underground storage tank for gasoline or the like having a ventpipe open to the atmosphere including a subsurface horizontal run buriedat such shallow depth as to be susceptible to having a dip formedtherein by vehicles travelling on the ground thereover and also havingan upright end part projecting above ground and open at its upper end,the combination therewith of means for trapping any liquid gasolinedischarged from said open end of said vent pipe, comprising a lower endhead secured to said upper end of said vent pipe and through which saidupper end of said vent pipe extends, a tubular shell secured to andrising from the rim of said lower end head, means within said tubularshell and arranged over the open upper end of said vent pipe anddeflecting laterally any liquid discharged therefrom, said vent pipebeing provided above said lower end head with a drain hole for returningsuch discharged liquid into said vent pipe, said tubular shell beingprovided with a'.

removable upper end head and said upper end head being provided at itscenter with an upright vent pipe and a cap arranged above said vent pipein spaced relation thereto, said vent pipe venting the chamber formed bysaid tubular shell and its end heads.

4. In an underground storage tank for gasoline or the like having a ventpipe open to the atmosphere including a subsurface horizontal run buriedat such shallow depth as to be susceptible to having a dip formedtherein by vehicles travelling on the ground thereover and also havingan upright end part projecting above ground and open at its upper end,the combination therewith of means for trapping any liquid gasolinedischarged from said open end of said vent pipe, comprising a lower endhead secured to said upper end of said vent pipe and through which saidupper end of said vent pipe extends, a tubular shell secured to andrising from the rim of said lower end head, and means within saidtubular shell and arranged over the open upper end of said vent pipe anddeflecting laterally any liquid discharged therefrom, said RefelflluflCited in file of this P9391!t vent pipe being provided above said lowerend head with UNITED STATES PATENTS a drain hole for returning suchdischarged liquid into 205 716 Allonas Jul 9 1878 said vent pipe, saiddeflecting means comprising a cap 223403 Stewart 1880 mounted over saidopen upper end of said vent pipe an 5 995314 Abs "June 13 1911 having amarginal skirt to deflect any liquid so discharged 1,306Z421 Feltz June10: 1919 downwardly as well as laterally. 1,545, 52 Rodriguez July 7,192.5 5. Apparatus as set forth in claim 4 wherein a tubular 7 1,966,998Steele July 17, 1934 screen is operatively interposed between said upperend 10 2,458,909 John Ian. 11, 1949 of said vent pipe and said cap.2,893,423 Seney July 7, 1959

